Sewerage network

We provide sewerage services to Dorset, Somerset, Bristol, most of Wiltshire and parts of Gloucestershire and Hampshire.

The network

Over the last five years, we have invested nearly £100 million to upgrade our sewerage network, including a £55 million investment in our sewerage network in north Bristol and a £39 million investment to improve sewerage infrastructure in Somerset.

Through our continued investment, we have also been able to consistently achieve 99.9% compliance with environmental standards at all of our water recycling centres.

White icon of a sewer pipe with flowing water coming exiting

Approx. 35,000

kilometres of sewers

White outline of a water treatment tower with water pumping out of it

Close to 400

water recycling centres

White icon of an engineer with a hard hat on

Around 2,200

sewage pumping stations

Sewage flooding

Sewage flooding is rare but when it does occur it can have devastating effects. Therefore, tackling it remains one of our key objectives.

Most flooding incidents occur due to blockages caused by inappropriate items being either flushed down the toilet (such as wet wipes) or poured down the sink (such as fats, oils and grease).

We have been working hard to improve how we monitor and maintain our sewers, while also helping customers avoid blockages by raising awareness about the impact of sewer misuse.

Identifying blockages on our network

In 2020, we trialled StormHarvester's Intelligent Sewer Suite at our Bath catchment to see if it could accurately predict potential sewer blockages as they begin to form.

During the trial, the machine learning technology detected more than 60 blockage formations in real-time, with a 92% accuracy in identifying early forming blockages.

Following the success of the trial, we are expanding the use of this artificial intelligence (AI) so it will cover all of our critical storm overflow monitors by 2024.

We are the first company in the world to commit to using AI technology across an entire sewer network to detect blockages, which will help us to prevent pollution and sewer flooding events.

Groundwater infiltration

Several locations in our region with ground chalk layers (or 'chalk strata') below the standing water level, can be affected by high groundwater levels which infiltrate the sewer network.

Our infiltration reduction plans continue to reduce the risk of groundwater entering sewers and drains. We proactively inspect more than 100km of sewers for signs of infiltration and have permanently sealed 6.1km of sewers where seepage was occurring.

It is a complicated issue so we continue to raise awareness on how groundwater can cause sewer flooding for our customers.